Subcutaneous electric field distribution system and methods

ABSTRACT

Apparatus and methods for dynamically controlling electric field distribution within tissue disposed at various depths beneath the skin at a target region of a patient&#39;s body by independently controlling the electric potential of each of a plurality of electrodes in relation to the electric potential of a ground pad. By controlling electric field distribution during a procedure, a target tissue at particular depths beneath the skin can be selectively heated relative to adjacent non-target tissue. At least one of the electrodes and the ground pad may comprise a spiral inductor comprising a substantially planar spiral of electrically conductive material.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of copending U.S. patent applicationSer. No. 12/144,948, with a filing date of Jun. 24, 2008, which claimsthe benefit of U.S. Provisional Application No. 61/207,877, filed Jun.5, 2008, the disclosure of which is incorporated herein by reference intheir entirety.

FIELD OF THE INVENTION

The present invention generally relates to systems and methods forcontrolling electric field distribution within a patient's tissues.

BACKGROUND OF THE INVENTION

The proportion of children, adolescents, and adults who are overweightor obese is increasing. The number of overweight people has doubled inthe last two to three decades, and such increases are found in all age,race, and gender groups.

Cellulite is a common skin condition related to the accumulation ofexcess subcutaneous fat (adipose tissue) within fibrous septae.Irregularities in the structure of the fibrous septae can create theappearance of cellulite, which is typically seen as an unsightlyirregular, dimpled skin surface. Cellulite is often found in abundancein overweight and obese individuals, e.g., on the thighs, hips, andbuttocks.

There is a demand for apparatus and procedures that will reduce theoverall volume of adipose tissue and/or reshape subcutaneous fat. Thereis also a demand for treatments that will decrease the appearance ofcellulite for cosmetic purposes.

Prior art interventions for decreasing or reshaping adipose tissueinclude liposuction and lipoplasty, massage, low level laser therapy,and external topical compositions, such as “cosmeceuticals,” or acombination of such treatments. Liposuction and lipoplasty are invasivesurgical techniques in which subcutaneous fat is excised and/orsuctioned from the body. These procedures may be supplemented by theapplication to the targeted adipose tissue of various forms of energy toemulsify the fat prior to its removal, e.g., by suction.

Although liposuction and lipoplasty can effectively remove subcutaneousfat, the invasive nature of these procedures presents the inherentdisadvantages of surgery, including high cost and extended recoverytimes, as well as the associated risks such as infection, excessivebleeding, and trauma.

Non-invasive interventions for subcutaneous fat reduction, or diminutionof the appearance of cellulite, including massage and low-level lasertherapy, are significantly less effective than surgical intervention.

Some cosmetic skin treatments effect dermal heating by applyingradiofrequency (RF) energy to the skin using surface electrodes. Thelocal heating is intended to tighten the skin by producing thermalinjury that changes the ultrastructure of collagen in the dermis, and/orresults in a biological response that changes the dermal mechanicalproperties. The literature has reported some atrophy of sub-dermal fatlayers as a complication to skin tightening procedures.

During electrosurgical procedures that target subcutaneous fat, thedepth of muscle tissue below the surface of the skin may greatlyinfluence the distribution of electric currents, and therefore theheating distribution within the tissues. Prior art apparatus and methodshave not adequately addressed electric current distribution insubcutaneous tissue in relation to variations in the thickness or depthof skeletal muscle tissue underlying a targeted tissue comprisingsubcutaneous fat.

US Patent Application Publication No. 2006/0036300 (Kreindel) discloseslipolysis apparatus having one or more protruding, terminal electrodes.In methods of Kreindel, a region of tissue may be deformed, and theelectrodes may contact both deformed and non-deformed skin.

U.S. Pat. No. 6,488,678 to Sherman discloses apparatus including acatheter having an array of electrodes at the catheter distal end, andadapted to position the electrodes at a biological site. A backplate ispositioned proximal to the biological site, such that the biologicalsite is interposed between the backplate and the electrodes. Powerprovided to the electrodes has a duty cycle with on and off periods.During a first segment of the on period, energy flows between thebackplate and an electrode, while during a second segment of the onperiod, energy flows between the electrodes. The flow of energy can becontrolled by adjusting the phase angle of the power.

U.S. Pat. No. 6,635,056 to Kadhiresan et al. discloses a systemincluding a catheter for use in ablation therapy, e.g., of cardiactissue, in which the system uses controllable differences in amplitudeof power signals to establish repetitive bipolar current flow betweensets of electrodes, and a backplate to establish unipolar current flow.

U.S. Pat. No. 7,151,964 to Desai discloses a multi-electrode catheterfor ablation of endocardiac tissues. The electrodes are adapted forbeing collapsed for introducing the catheter into the patient's body,and for being fanned out into an array during ablation of tissue, suchas endomyocardium. In a preferred embodiment of the '964 patent, atwo-phase RF power source is used with an orthogonal electrode catheterarray comprising one central electrode and four peripheral electrodes.The central electrode is connected to ground voltage of the powersupply; and the peripheral electrodes form two diagonal pairs connectedto two individually phased voltages.

U.S. Patent Application Publication No. 2007/0203482 (Ein Gal) disclosesa system including at least two target electrodes, at least one returnelectrode, and at least two RF power sources in electrical communicationwith the electrodes. Each target electrode defines a separate monopolarenergy delivery channel, the at least one return electrode being commonto both channels. The target electrodes are operable in a bipolar mode.A waveform manipulator controls and manipulates RF energy waveforms tothe target electrodes to selectively provide pure monopolar, purebipolar and a blend of monopolar and bipolar modes of energy deliveryfor RF tissue ablation.

It can be seen that there is a need for an effective modality by whichsubcutaneous fat tissue may be non-invasively reshaped, and/or sculptedfor the cosmetic improvement of human skin and/or body shape. There is afurther need for a non-invasive procedure for effectively andefficiently decreasing the volume of subcutaneous adipose tissue in aperson who may be obese or overweight.

SUMMARY OF THE INVENTION

According to one aspect of the invention, a system for treating a targetissue of a patient includes a handpiece configured for contacting skinof the patient, an electrosurgical generator coupled to the handpiece,and a ground pad coupled to the electrosurgical generator. The handpieceincludes at least a first electrode and a second electrode, and thesystem is configured for independently controlling an electric potentialof each of the first electrode, the second electrode, and the groundpad, such that the system is adapted for dynamically controllingelectric current distribution relative to a depth of the target tissuebeneath the skin.

According to another aspect of the invention there is provided a systemfor treating a patient, the system including a ground pad, anelectrosurgical generator coupled to the ground pad, and a handpiececoupled to the electrosurgical generator. The handpiece includes a shellhaving a treatment chamber therein, a treatment surface within thetreatment chamber, and a plurality of electrodes disposed on thetreatment surface. The system is configured for independentlycontrolling an electric potential of each of the electrodes relative toa reference potential of the ground pad.

According to yet another aspect of the invention, a method for treatinga patient includes providing a handpiece having at least a firstelectrode and a second electrode; disposing a ground pad against anon-target region of the patient's skin; contacting the handpieceagainst the patient's skin, such that at least the first electrode andthe second electrode contact a target region of the patient's skin; andindependently controlling an electric potential of each of the firstelectrode, the second electrode, and the ground pad. The method furtherincludes applying electrical energy to a target tissue via at least oneof the first electrode and the second electrode; and dynamicallycontrolling electric current distribution relative to a depth beneaththe skin of the target issue, such that the target tissue is selectivelyheated. The target tissue is disposed beneath the target region of thepatient's skin.

According to still a further aspect of the invention, there is provideda method for selectively heating a target tissue of a patient, whereinthe method includes providing a handpiece having a plurality ofelectrodes, a treatment chamber, and a flange; contacting a ground padagainst a non-target region of the patient's skin; contacting the flangeagainst the patient's skin, such that the flange surrounds a targetregion of the patient's skin; drawing the target tissue into thetreatment chamber; and maintaining the ground pad at a referencepotential. The method further includes independently controlling anelectric potential of each of the electrodes relative to the referencepotential; and applying electrical energy to the target tissue via atleast one of the electrodes, such that electric current distributionrelative to the target tissue is dynamically controlled to provideselective heating of the target tissue. The target tissue comprisessubcutaneous fat disposed beneath the target region of the patient'sskin.

These and other features, aspects, and advantages of the presentinvention may be further understood with reference to the drawings,description, and claims which follow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A schematically represents an electrosurgical system for treatinga patient, according to an embodiment of the invention;

FIG. 1B schematically represents an electrosurgical system for treatinga patient, according to another embodiment of the invention;

FIG. 2A schematically represents electric current distribution between afirst electrode and a second electrode in contact with the skin of apatient in a bipolar mode of operation;

FIG. 2B schematically represents electric current distribution between aground pad and first and second electrodes, with the first and secondelectrodes in contact with the skin of a patient, in a monopolar mode ofoperation;

FIG. 2C schematically represents electric current distribution between afirst electrode, a second electrode, and a ground pad, with the firstand second electrodes in contact with a target region of skin of apatient, according to an aspect of the invention;

FIG. 3A is a block diagram schematically representing an electrosurgicalsystem including a control unit in communication with a handpiece havinga plurality of electrodes and a plurality of temperature sensors,according to an embodiment of the invention;

FIG. 3B is a block diagram schematically representing an electrosurgicalsystem including a vacuum unit in communication with a handpiece,according to another aspect of the invention;

FIG. 4 is a block diagram schematically representing a handpiece havinga cooling unit and a vibration unit, according to another embodiment ofthe invention;

FIGS. 5A-B each show a plan view of a handpiece, as seen from above,according to two different embodiments of the invention;

FIG. 5C is a side view of the handpiece of FIG. 5A or 5B;

FIG. 5D is a sectional view of the handpiece of FIGS. 5A-C, as seenalong the line 5D-5D of FIG. 5C;

FIG. 5E shows a plan view of the underside of the handpiece of FIG. 5A,as seen along the line 5E/F-5E/F of FIG. 5C;

FIG. 5F shows a plan view of the underside of the handpiece of FIG. 5B,as seen along the line 5E/F-5E/F of FIG. 5C;

FIG. 6A is a plan view of a treatment surface for a handpiece, accordingto another embodiment of the invention;

FIG. 6B is a sectional view of the treatment surface as seen along thelines 6B-6B of FIG. 6A;

FIG. 7 schematically represents a spiral of electrically conductivematerial for forming an electrode, as seen in plan view, according toanother embodiment of the invention;

FIG. 8A schematically represents a spiral inductor, as seen in planview, according to an embodiment of the invention;

FIG. 8B schematically represents a spiral inductor, as seen in planview, according to another embodiment of the invention;

FIG. 9A schematically represents a portion of a spiral inductor for anelectrode, as seen in side view, according to an embodiment of theinvention;

FIG. 9B schematically represents a portion of a spiral inductor for anelectrode, as seen in side view, according to another embodiment of theinvention;

FIG. 10A schematically represents a handpiece, as seen from the side,showing an empty treatment chamber of the handpiece in relation to atarget region of skin of a patient, according to one aspect of theinvention;

FIG. 10B schematically represents the handpiece of FIG. 10A showing atarget tissue of the patient disposed within the treatment chamber,according to another aspect of the invention;

FIG. 11A is a flow chart schematically representing steps in a methodfor treating a patient, according to another embodiment of theinvention;

FIG. 11B is a flow chart schematically representing steps in a methodfor selectively heating a target tissue of a patient, according toanother embodiment of the invention;

FIG. 12A schematically represents a portion of a patient's body disposedin relation to a handpiece and a ground pad, according to anotherembodiment of the invention; and

FIG. 12B schematically represents a patient's body, as seen in themedial direction, showing various regions of the body which may comprisetarget and non-target regions of the patient, according to anotherembodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description is of the best currently contemplatedmodes of carrying out the invention. The description is not to be takenin a limiting sense, but is made merely for the purpose of illustratingthe general principles of the invention, since the scope of theinvention is best defined by the appended claims.

Broadly, the present invention provides methods and apparatus fortreating or selectively heating a target tissue of a patient in anon-invasive procedure. As a non-limiting example, the instant inventionmay be used to selectively heat, remove, and or sculpt adipose tissue,such as may be present in subcutaneous fat and/or cellulite.

During electrosurgical procedures that target subcutaneous fat, theeffective depth of skeletal muscle tissue below the surface of the skinmay greatly influence the distribution of electric currents, andtherefore the heating distribution within the tissues. The skeletalmuscle depth can vary widely from patient to patient, as well as fromregion to region of a given patient's body. To tailor a procedure for aparticular region of a given patient's body and to compensate for widevariations in tissue, the instant invention actively controls thedistribution of electric currents, and therefore the distribution ofheat, e.g., relative to tissue depth below the skin surface. Suchcurrent distribution control can be achieved by adjusting or controllingthe potential difference between at least two (active) electrodesdisposed on a target region of the skin surface; and, at the same time,by controlling the potential difference between at least one of theelectrodes relative to a ground pad.

Apparatus of the invention may include a handpiece having a plurality ofelectrodes configured for contacting the patient's skin, wherein anelectric potential of at least two of the electrodes may beindependently controlled during a procedure to dynamically controlelectric current distribution within a patient's tissue relative to adepth of a target tissue disposed beneath, and adjacent to, thepatient's skin.

Apparatus and systems of the instant invention may include a handpiececonfigured for contacting a treatment surface of the handpiece against atarget region of the skin surface, wherein a plurality of electrodes maybe disposed on the treatment surface, such that at least two of theelectrodes contact the target region of skin during treatment of thepatient. At least one of the electrodes may be a substantially planarspiral inductor, and each electrode may be affixed to and aligned withthe treatment surface. Systems and apparatus of the instant inventionmay further include a ground pad. The ground pad may comprise asubstantially planar spiral inductor configured for contacting thepatient's skin. Each spiral inductor (of the electrodes and/or groundpad) may be formed from a substantially planar spiral of electricallyconductive material.

During a procedure according to an embodiment of the instant invention,the ground pad may be disposed in contact with a non-target region ofthe skin surface of the patient. The non-target region of the skin maybe remote from the target region of the skin, such that at least onelayer of subcutaneous fat, at least one layer of skeletal muscle, and/orat least one bone of the patient may be disposed between the handpieceand the ground pad.

FIG. 1A schematically represents an electrosurgical system for treatinga patient, according to an embodiment of the invention. System 10 mayinclude an electrosurgical generator 20, a ground pad 40, and ahandpiece 50. Ground pad 40 and handpiece 50 may be coupled toelectrosurgical generator 20. Ground pad 40 may function as a returnelectrode. During a procedure involving system 10, ground pad 40 may belocated on the skin of the patient at a location remote from thesurgical site/handpiece 50. System 10 may further include a control unit30. In an embodiment, control unit 30 may be integral with generator 20.In another embodiment, control unit 30 may comprise a separate device.

Handpiece 50 may include a plurality of electrodes 60 a-n. Each ofelectrodes 60 a-n may be in electrical communication with control unit30. System 10 may be configured for independently controlling, e.g., viacontrol unit 30, an electric potential of each of electrodes 60 a-n. Forexample, during a procedure system 10 may be configured forindependently controlling or dynamically adjusting an electric potentialof each of electrodes 60 a-n relative to a reference potential of groundpad 40. In an embodiment, system 10 may be configured for independentlycontrolling a potential difference between: i) a first electrode 60 aand ground pad 40, ii) a second electrode 60 b and ground pad 40, andiii) first electrode 60 a and second electrode 60 b. In an embodiment,system 10 may be configured for maintaining ground pad 40 at a referencepotential. Such reference potential may correspond to ground (earth)potential. In an embodiment, system 10 may be configured for providing afirst AC voltage to first electrode 60 a and for providing a second ACvoltage to second electrode 60 b. System 10 may be configured fordynamically controlling, e.g., via control unit 30, a phase differencebetween the first and second AC voltages, such that a potentialdifference between first and second electrodes 60 a-b can be controlledduring a procedure. Dynamic control of the potential difference betweenfirst and second electrodes 60 a-b may include adjusting a phasedifference between the first and second AC voltages, i.e., the phasedifference between the first and second AC voltages may determine thepotential difference between first and second electrodes 60 a-b.

What has been described herein with reference to controlling electricpotential of first and second electrodes 60 a-b may similarly beapplicable to each of electrodes 60 a-n. The electric potential of eachof electrodes 60 a-n may be dynamically controlled during a procedure,e.g., to selectively heat a target tissue to an appropriate temperatureor temperature range, relative to adjacent non-target tissue.

In an embodiment, ground pad 40 may comprise a spiral inductor 62 (see,e.g., FIGS. 8A-B). In an embodiment, one or more of electrodes 60 a-nmay similarly comprise a spiral inductor. In an embodiment, handpiece 50may have a substantially planar treatment surface 53, i.e., treatmentsurface 53 may occupy a single plane (see, e.g., FIGS. 6A-B). In otherembodiments, handpiece 50 may have a treatment surface 53 that occupiesa plurality of different planes (see, e.g., FIGS. 5D-E).

During use of system 10, e.g., for performing an electrosurgicalprocedure, a patient's body, PB, or a portion thereof, may be juxtaposedbetween ground pad 40 and handpiece 50. System 10 may be adapted fortreating a patient for the reduction of cellulite, for sculpting theexternal surface of the patient's body, and for decreasing an amount ofsubcutaneous fat of the patient, or a combination thereof, or similarprocedures. System 10 may be used for improving the appearance of theexternal portion of a patient's body, for reduction in body weight ofthe patient, or for a combination thereof, or for similar purposes.Typically, during a procedure involving system 10, at least one layer ofsubcutaneous fat, at least one layer of skeletal muscle, and/or at leastone bone of the patient may be disposed between handpiece 50 and groundpad 40 (see, e.g., FIG. 12B).

FIG. 1B schematically represents an electrosurgical system for treatinga patient, according to another embodiment of the invention. System 10of FIG. 1B may have components, elements, and features generally asdescribed with reference to FIG. 1A (supra), including handpiece 50,generator 20, ground pad 40, and control unit 30. Handpiece 50 andground pad 40 may be coupled to control unit 30. Control unit 30 may beintegral with generator 20. The invention is not limited to anyparticular configuration for system 10.

Handpiece 50 of FIG. 1B may include at least two electrodes, includingfirst electrode 60 a and second electrode 60 b. In an embodiment, the atleast two electrodes may be disposed at least substantially oppositeeach other, e.g., first electrode 60 a may be disposed opposite secondelectrode 60 h (see, e.g., FIGS. 5E and 6A).

With further reference to FIG. 1B, handpiece 50 may further include atleast one temperature sensor 54. Temperature sensor 54 may be incommunication with control unit 30. Temperature sensor 54 may beconfigured for sensing temperature values of a portion of a targetregion of skin. In an embodiment, system 10 may be configured forsensing a temperature value of a target tissue, e.g., via extrapolationof a sensed skin temperature. Temperature sensor 54 may provide sensedtemperature values to control unit 30. Control unit 30 may be configuredfor independently controlling the electric potential of each of firstand second electrodes 60 a-b, e.g., in response to the sensedtemperature values. Control unit 30 may be further configured forindependently controlling the electric potential of ground pad 40; forexample, system 10 may be configured for controlling the electricpotential of ground pad 40 independently of the control of the electricpotential of first and second electrodes 60 a-b. In an embodiment,handpiece 50 may include a plurality of temperature sensors 54 (see,e.g., FIG. 3A).

FIG. 2A schematically represents electric current distribution (brokenlines) between a first electrode 60 a and a second electrode 60 b, bothof which may be disposed on or within a single handpiece 50 (see, e.g.,FIGS. 1A-B). (Handpiece components other than first and secondelectrodes 60 a, 60 b are omitted from FIG. 2A for the sake of clarity.)Both of first and second electrodes 60 a, 60 b may be in contact with atarget region, TR, of skin of a patient, in a bipolar mode of operation.First and second electrodes 60 a, 60 b are shown schematically inrelation to a simplified representation of tissue layers of thepatient's body, PB, including the skin, SK, subcutaneous fat, SF, andskeletal muscle. MU. (The term “skeletal muscle” is used herein todistinguish the muscle adjacent to the subcutaneous fat from other,fundamentally different forms of muscle found in the human body, namely“cardiac muscle” of the heart and “smooth muscle” of organs such as thestomach. That is to say, the term “skeletal muscle” as used hereinexcludes both smooth muscle and cardiac muscle.)

First and second electrodes 60 a, 60 b may be coupled to anelectrosurgical generator or power supply (not shown in FIGS. 2A-C).First electrode 60 a may be controlled at, or adjusted to, a firstelectric potential V₁ and second electrode 60 b may be controlled at, oradjusted to, a second electric potential V₂, such that a potentialdifference exists between first and second electrodes 60 a, 60 b. Inthis configuration, electric current tends to flow substantiallyhorizontally (or transversely) between first and second electrodes 60 a,60 b. The type of electric current distribution within the tissue asshown in FIG. 2A may result in only shallow heating in the region of theskin; while a deeper target tissue in the subcutaneous fat layer mayreceive little or no heating from first and second electrodes 60 a-b. InFIG. 2A, a ground pad (not shown) may be absent or disconnected from thepower supply or generator.

FIG. 2B schematically represents electric current distribution (brokenlines) between a ground pad and first and second electrodes, with thefirst and second electrodes in contact with a target region, TR, of skinof a patient, in a monopolar mode of operation. In FIG. 2B, first andsecond electrodes 60 a, 60 b as well as ground pad 40 are shown inrelation to the skin, subcutaneous fat, and skeletal muscle layers.Ground pad 40 may be maintained at ground potential, V₀. Each of firstand second electrodes 60 a, 60 b may be controlled or maintained at anelectric potential V₁. In this configuration, there is no potentialdifference between first and second electrodes 60 a, 60, and accordinglyelectric current tends to flow substantially vertically from first andsecond electrodes 60 a, 60 b to ground pad 40, resulting in deeper andmore diffuse heating in the skeletal muscle layer (beneath thesubcutaneous fat), while the subcutaneous fat may again receive littleheating via first and second electrodes 60 a-b.

FIG. 2C schematically represents electric current distribution (brokenlines) relative to a first electrode, a second electrode, and a groundpad, according to an embodiment of the invention. In FIG. 2C, first andsecond electrodes 60 a, 60 b are shown in contact with a target region,TR, of skin, SK of a patient. A layer of subcutaneous fat, SF, and askeletal muscle layer, MU, are shown in relation to the skin. In anembodiment, ground pad 40 may be maintained at a reference potential,V_(R). In an embodiment, the reference potential may comprise ground(earth) potential, e.g., V_(R) may equal V₀. In another embodiment, theground pad 40 may be controlled or maintained at a reference potentialother than ground potential. The electric potential of each of first andsecond electrodes 60 a, 60 b, as well as that of ground pad 40, may beindependently controlled or adjusted via control unit 30 (see, e.g.,FIGS. 1A-B, 3A). For example, an electric potential of first and secondelectrodes 60 a, 60 b may be controlled at electric potentials V₃ andV₄, respectively, wherein V₃ and V₄ are different, such that a potentialdifference exists between first and second electrodes 60 a, 60 h. Atleast one of V₃ and V₄ may be different from V_(R), such that apotential difference exists between at least one of first and secondelectrodes 60 a, 60 b with respect to ground pad 40. In an embodiment,each of V₃, V₄, and V_(R) may represent a different electric potential,such that a potential difference exists between each of: i) firstelectrode 60 a and second electrode 60 b, ii) first electrode 60 a andground pad 40, and iii) second electrode 60 b and ground pad 40.

During a procedure according to the instant invention, handpiece 50 (notshown in FIGS. 2A-C) and ground pad 40 may be disposed or configured inrelation to the patient's body such that at least one bone of thepatient (not shown), as well as at least one layer of subcutaneous fatand at least one layer of skeletal muscle may be disposed betweenhandpiece 50 and ground pad 40 (see, e.g., FIG. 12A). In this regard, itis well known in the art that skeletal muscle is disposed beneathsubcutaneous fat on the torso and the upper and lower limbs of the humanbody, and that skeletal muscle is attached to bones.

In the configuration of FIG. 2C, electric current distribution can bedynamically controlled, relative to a depth beneath the skin of thetarget tissue, TT, by controlling the values of V₃, V₄, and V_(R). Bydynamically controlling the electric current distribution at different,defined depths beneath the skin, a target tissue at particular depthscan be selectively heated. For example, subcutaneous fat, SF, can beselectively heated in relation to the skeletal muscle layer, MU, and theadjacent target region of the skin. The skeletal muscle layer maycomprise, as non-limiting examples, the external oblique muscle of theabdomen, the pectoralis major muscle of the thorax, the gluteus maximusof the buttock, the deltoid muscle of the shoulder, the trapezius musclebetween the back and neck, the biceps brachii or the triceps brachiimuscles of the arm, the latissimus dorsi muscle of the back, or therectus femoris, biceps femoris, vastus lateralis or vastus medialismuscles of the thigh. Each of the skeletal muscles of the human bodydescribed herein is well known in the art (see, e.g., Atlas of HumanAnatomy, Second Edition (1999), by Frank H. Netter, M.D. (Arthur F.Dailey II, Ph.D., Consulting Editor), Novartis, East Hanover, N.J., thecontents of which are incorporated by reference herein).

A schematic representation of an exemplary zone of selective heating,ZH, disposed between the skin and muscle layer is shown in FIG. 2C. Itis to be understood, however, that the invention is not limited to aparticular electric current distribution or zone of selective heating atany particular depth beneath the skin. Rather, the electric currentdistribution within the tissue, and hence the zone of selective heating,can be dynamically controlled during a procedure by controlling thevalues of electric potential, V₃, V₄, and V_(R). In other embodiments,electric current distribution within the patient's tissue may becontrolled according to the same principles using apparatus having morethan two electrodes (see, e.g., FIGS. 1A, 3A, 5E, and 6A).

FIG. 3A is a block diagram schematically representing an electrosurgicalsystem, according to an embodiment of the invention. System 10 mayinclude a handpiece 50, a generator 20, a ground pad 40, and a controlunit 30. Handpiece 50 and ground pad 40 may be coupled to control unit20. Control unit 30 may be integral with generator 20. The invention isnot limited to any particular configuration for system 10.

With further reference to FIG. 3A, handpiece 50 may include a pluralityof electrodes 60 a-n. Each of electrodes 60 a-n may be configured forcontacting the skin of a patient. For example, handpiece 50 may bedisposed in relation to a patient's body such that each of electrodes 60a-n contacts a target region of skin adjacent to a target tissue, suchas subcutaneous fat disposed between the target region of skin and askeletal muscle layer.

Handpiece 50 may further include a plurality of temperature sensors 54a-n. Each of temperature sensors 54 a-n may be configured for contactingthe skin of the patient. In an embodiment, temperature sensors 54 a-nmay be disposed within a treatment chamber (not shown in FIG. 3A) ofhandpiece 50. In an embodiment (not shown), temperature sensors 54 a-nmay be disposed at the periphery, corners, and/or sides of handpiece 50.Each of temperature sensors 54 a-n may be configured for sensingtemperature values of a portion of the target region of skin, whereinthe target region of skin may be disposed adjacent to the target tissue.In an embodiment, the target tissue may comprise subcutaneous adiposetissue disposed beneath the target region of skin of the patient (see,e.g., FIG. 2C). Each of temperature sensors 54 a-n may be incommunication with control unit 30 for providing thereto sensedtemperature values. Each of electrodes 60 a-n may be in communicationwith control unit 30. Generator 20 may include an RF power source(not-shown) in communication with control unit 30. Control unit 30 maybe configured for independently controlling an electric potential ofeach of electrodes 60 a-n relative to an electric potential of groundpad 40. The electric potential of electrodes 60 a-n and of ground pad 40may be dynamically controlled during a procedure, substantially asdescribed hereinabove (e.g., with reference to FIGS. 1A and 2C). In anembodiment, such control of electric potential of electrodes 60 a-n maybe performed in response to temperature values sensed by at least one oftemperature sensors 54 a-n. Control unit 30 may include an analog todigital converter in communication with a CPU, microprocessor, ormicrocontroller (not shown), and the like; however, the invention is notto be limited to a control unit 30 having particular components,circuitry, or configurations.

Although FIG. 3A shows three temperature sensors 54 a-n, other numbersof sensors are also within the scope of the invention. Similarly,although FIG. 3A shows three electrodes 60 a-n, other numbers ofelectrodes are also within the scope of the invention. As a non-limitingexample, handpiece 50 may include from two to ten or more electrodes 60a-n, usually from two to eight electrodes 60 a-n, and often from two tosix electrodes 60 a-n.

FIG. 3B is a block diagram schematically representing an electrosurgicalsystem; according to an embodiment of the invention. System 10 mayinclude a handpiece 50 coupled to an electrosurgical generator 20.Handpiece 50 may be configured for contacting a target region of theskin, SK, located above or adjacent to a target tissue, TT, of thepatient. Handpiece 50 may include various elements and characteristicsas described hereinabove (e.g., with reference to FIGS. 1A and 3A). Inan embodiment, system 10 may further optionally include a vacuum unit70. Vacuum unit 70 may be in fluid communication with handpiece 50. Inan embodiment, handpiece 50 may be configured for drawing a targettissue, such as a volume of subcutaneous fat, within a treatment chamberof handpiece 50 (see, e.g., FIG. 5D).

With further reference to FIG. 3B, system 10 may further include aground pad 40, which may be configured for contacting the skin of thepatient. System 10 may be configured for contacting ground pad 40against a non-target region, NTR, of the skin during a procedure,wherein the non-target region of the patient's skin may be disposed at alocation remote from the target region of the patient's skin. Forexample, during a procedure at least one layer of subcutaneous fat, atleast one layer of skeletal muscle, and/or at least one bone of thepatient may typically be disposed between the handpiece at the targetregion of the skin and the ground pad at the non-target region of theskin. As another example, the handpiece and the target region of theskin may be disposed at an anterior position on the patient's body,while the ground pad and the non-target region of the skin may bedisposed at a posterior position on the patient's body.

In an embodiment, system 10 may further include a user interface 80.User interface 80 may be coupled to, or in signal communication with,electrosurgical generator 20, for inputting thereto parameters relatedto a particular procedure. Such parameters may include thresholdtemperature values for the target region of skin or target tissue,value(s) of a reference potential for ground pad 40, and the like. Userinterface 80 may also be coupled to, or in signal communication with,vacuum unit 70, for qualitatively and/or quantitatively controlling theapplication of suction, via vacuum unit 70, to handpiece 50 (see, e.g.,FIG. 10B).

FIG. 4 is a block diagram schematically representing a handpiece,according to another embodiment of the invention. Handpiece 50 mayinclude a plurality of electrodes 60 a-n, a treatment surface 53, and acontact plate 55. Electrodes 60 a-n may be disposed on treatment surface53. Contact plate 55 may be at least substantially planar. Contact plate55 may be contiguous with treatment surface 53. In an embodiment,handpiece 50 may further include a cooling unit 56. Cooling unit 56 maybe disposed against or adjacent to contact plate 55. In an embodiment,cooling unit 56 may be disposed at least substantially parallel tocontact plate 55. Contact plate 55 may be configured to function inconcert with cooling unit 56 to cool a target region of the patient'sskin during a procedure. In an embodiment, handpiece 50 may stillfurther include a vibration unit 57 configured for vibrating handpiece50 during a procedure.

FIG. 5A is a plan view of a handpiece, as seen from above, according toan embodiment of the invention. In the embodiment of FIG. 5A, handpiece50 may have a substantially square or rectangular shape or outline. FIG.5B is a plan view of a handpiece, as seen from above, according toanother embodiment of the invention. In the embodiment of FIG. 5B,handpiece 50 may have a substantially circular or round shape oroutline. Naturally, other shapes or outlines for handpiece 50 are alsowithin the scope of the invention.

FIG. 5C is a side view of the handpiece of FIG. 5A or 5B. Handpiece 50may include a shell 51. Further detail of handpiece 50 is shown in FIGS.5D-F (infra). FIG. 5D is an enlarged sectional view of the handpiece ofFIGS. 5A-C, as seen along the line 5D-5D of FIG. 5C. Handpiece 50 mayinclude shell 51, a flange 58, a treatment surface 53, and a contactplate 55. Handpiece 50 may further include a plurality of electrodes 60.Each electrode 60 may be coupled to control-unit 30 (see, e.g., FIGS.1A-B), and an electric potential of each electrode 60 may beindependently controlled relative to a ground pad potential during aprocedure to dynamically control electric current distribution within oradjacent to a target tissue (e.g., subcutaneous adipose tissue) of thepatient, substantially as described hereinabove (e.g., with reference toFIGS. 1A and 2C).

In an embodiment, each electrode 60 may be affixed to and aligned withat least a portion of treatment surface 53. Flange 58 may define adistal rim of handpiece 50, and electrodes 60 may be disposed proximalto flange 58. For example, electrodes 60 may be recessed within shell51/treatment chamber 59. Treatment surface 53 may comprise anelectrically insulating or dielectric material. In an embodiment,handpiece 50 may further include a plurality of temperature sensors 54a-n (see, e.g., FIG. 3A). One or more portions of treatment surface 53,and at least one of electrodes 60, may be at least substantially planar.Treatment surface 53 and contact plate 55 may jointly define treatmentchamber 59. In an embodiment, handpiece 50 may be configured forreceiving at least a portion of a target tissue within treatment chamber59 during a procedure (see, e.g., FIG. 10B).

In an embodiment, handpiece 50 may further include a cooling unit 56.Cooling unit 56 may be configured for cooling contact plate 55. Contactplate 55 may be at least substantially planar. Contact plate 55 may becontiguous with treatment surface 53. Cooling unit 56 may be disposedagainst or adjacent to contact plate 55. In an embodiment, cooling unit56 may be disposed at least substantially parallel to contact plate 55.Contact plate 55 may be configured for cooling a portion of thepatient's skin during a procedure. In an embodiment, cooling unit 56 maycomprise a thermoelectric cooler (not shown). The cold side of such athermoelectric cooler (TEC) may be disposed against, or adjacent to,contact plate 55. The hot side of the TEC may be cooled via fluid (e.g.,water) flow (not shown). Cooling unit 56 may be configured for coolingcontact plate 55 to a temperature down to zero (0°), typically to atemperature in the range of zero (0°) to about 30° C., usually to atemperature in the range of about 10° to 25° C., and often to atemperature in the range of about 16° to 22° C.

In an embodiment, handpiece 50 may still further include a vibrationunit 57. As a non-limiting example, vibration unit 57 may comprise aneccentric rotor, which may be of the type shown and described incommonly-owned U.S. application Ser. No. 11/851,335, SYSTEM AND METHODFOR DERMATOLOGICAL TREATMENT USING ULTRASOUND, filed Sep. 6, 2007.During a procedure, vibration unit 57 may be driven or activated tovibrate at least one of handpiece 50 and target tissue disposed withintreatment chamber 59.

FIG. 5E shows a plan view of the underside of handpiece 50 of FIG. 5A,as seen along the line 5E/F-5E/F of FIG. 5C. In the embodiment of FIG.5E, handpiece 50 may have a substantially square or rectangular shape oroutline. FIG. 5E shows flange 58, contact plate 55, and a plurality ofelectrodes 60 disposed on treatment surface 53. As shown, electrodes 60may be disposed at least substantially opposite each other on treatmentsurface 53. Flange 58, contact plate 55, and treatment surface 53 mayjointly define treatment chamber 59 (see, e.g., FIGS. 5D and 10A). Inthe embodiment of FIG. 5E, treatment surface 53 may occupy at least twodifferent planes. At least two of electrodes 60 may be disposed in atleast two different planes within treatment chamber 59. In anembodiment, each plane, or each substantially planar portion oftreatment surface 53, may have a separate electrode 60 disposed thereon.Electrodes 60 may be configured to accommodate various geometries oftreatment surface 53. Each electrode 60 may have a substantiallyelongate or rectangular shape.

In an embodiment, at least one of electrodes 60 may comprise a spiralinductor 62 (see, e.g., FIGS. 8A-B). In some embodiments, each ofelectrodes 60 may comprise a spiral inductor 62. Each spiral inductormay comprise a spiral 64 of an electrically conductive metal (see, e.g.,FIGS. 7 and 8A-9B). An active electrode comprising a spiral inductor wasdisclosed in commonly assigned, co-pending U.S. patent application Ser.No. 11/966,895, entitled “High Conductivity Inductively EqualizedElectrodes and Methods,” the disclosure of which is incorporated byreference herein in its entirety.

In an embodiment of the instant invention, each spiral inductor may havea substantially trapezoidal shape, e.g., comprising a quadrilateraloutline having two parallel sides and two non-parallel sides. A spiralelectrode having such a quadrilateral outline may also have roundedcorners (not shown). In the embodiment of FIG. 5E, treatment chamber 59may have a substantially frusto-pyramidal (truncated pyramid) shape. Ahandpiece having a substantially frusto-pyramidal, frusto-conicl(truncated cone), or dome shaped treatment chamber is disclosed incommonly assigned, co-pending U.S. patent application Ser. No.12/134,119, entitled “Dynamically Controllable Multi-electrode Apparatus& Methods,” filed on even date herewith, the disclosure of which isincorporated by reference herein in its entirety.

FIG. 5F shows a plan view of the handpiece of FIG. 5B, as seen along theline 5E/F-5E/F of FIG. 5C. In the embodiment of FIG. 5F, handpiece 50may have a substantially round or circular shape or outline. FIG. 5Ashows flange 58, contact plate 55, and a plurality of electrodes 60disposed on treatment surface 53. Flange 58, contact plate 55, andtreatment surface 53 may jointly define treatment chamber 59 (see, e.g.,FIG. 10B). Each electrode 40 may be configured to accommodate variousgeometries of treatment surface 53. In an embodiment, one or more ofelectrodes 60 may comprise a spiral inductor 62, substantially asdescribed with reference to FIG. 5E. As shown, each spiralinductor/electrode 62/60 may have a substantially arcuate shape oroutline. Other shapes and outlines for spiral inductors/electrodes 62/60are also within the scope of the invention.

In the embodiment of FIG. 5F, treatment chamber 59 may typically have asubstantially frusto-conical (truncated cone) shape. However, it is tobe understood that the invention is by no means limited to a handpiecehaving a treatment chamber of a particular shape or geometry.

In an embodiment, handpiece 50 may include a treatment surface 53configured for contacting an area of the external surface of the skin ofat least about 10 cm², and often treatment surface 53 may be configuredfor contacting an area of the external surface of the skin of at leastabout 100 cm². Handpiece 50 may further include various other elements,features, and characteristics, e.g., as described with reference toFIGS. 1A-B, 3A, and 4.

FIG. 6A is a plan view of a treatment surface of a handpiece, accordingto another embodiment of the invention. Treatment surface 53′ may be atleast substantially planar. Handpiece 50 may include a plurality ofelectrodes 60 disposed on treatment surface 53′. Each electrode 60 maybe coupled to control unit 30 (see, e.g., FIGS. 1A-B), and an electricpotential of each electrode 60 may be independently controlled oradjusted, e.g., relative to a ground pad potential, during a procedure,substantially as described hereinabove (e.g., with reference to FIGS. 1Aand 2C). As shown, electrodes 60 may be disposed at least substantiallyopposite each other on treatment surface 53′. Although electrodes 60 areshown in FIG. 6A as being substantially oval in outline, otherconfigurations for electrodes 60 are also contemplated under theinvention. Furthermore, although four (4) electrodes 60 are shown inFIG. 6A, other numbers of electrodes 60 are also within the scope of theinvention.

FIG. 6B is a sectional view of a portion of the handpiece of FIG. 6A, asseen along the lines 6B-6B of FIG. 6A. As can be seen from FIG. 6B, eachof electrodes 60 may be at least substantially planar. In an embodiment,each of electrodes 60 may comprise a spiral inductor (see, e.g., FIGS. 7and 8A-B). During use of handpiece 50, treatment surface 53′ may bedisposed against a planar or non-planar target region of the patient'sskin (not shown in FIG. 6B). In an embodiment, handpiece 50 may beforced against a non-planar target region of the patient's skin suchthat the skin and adjacent subcutaneous fat may at least substantiallyconform to treatment surface 53′.

FIG. 7 schematically represents a spiral of electrically conductivematerial, as seen in plan view, according to another embodiment of theinvention. Spiral 64 may include a plurality of turns 65 and an innerterminus 67 a. In an embodiment, each electrode 60 of handpiece 50 (see,e.g., FIGS. 5D-F and 6A-B) may comprise a spiral 64. In an embodiment,ground pad 40 of system 10 may similarly comprise a spiral 64. Althoughspiral 64 of FIG. 7 is shown as substantially round, otherconfigurations are also within the scope of the invention. Spiral 64 maycomprise a spiral trace of an electrically conductive metal, such as Cu,Al, or various alloys, as non-limiting examples. In an embodiment,spiral 64 may comprise a filament of the electrically conductive metal,wherein the filament may be disposed on a support layer 68 (see, e.g.,FIGS. 8A-9B). Only a few of the radially inner turns of spiral 64 areshown in FIG. 7, whereas spiral 64 in its entirety may comprise fromabout 10 to 200 or more turns, typically from about 10 to 150 turns, andoften from about 15 to 100 turns.

As shown in FIG. 7, spiral 64 may have a pitch, P_(t), representing aradial distance between the radial midpoints of adjacent turns 65. Thepitch of spiral 64 may be in the range of from about 0.1 nm i to 10 mmor more, typically from about 0.2 mm to 9 mm, often from about 0.25 to 5mm, and in some embodiments from about 0.3 to 1.5 mm. In an embodiment,the pitch of spiral 64 may be constant or substantially constant. Inother embodiments, the pitch of spiral 64 may vary.

Turns 65 of spiral 64 may have a width, W_(t), wherein the width, W_(t),is a radial distance across each turn 65. The width of each of turns 65may typically be in the range of from about 0.05 mm to 10 mm or more,typically from about 0.15 to 9 mm, often from about 0.2 to 5 mm, and insome embodiments from about 0.25 to 1.5 mm. In an embodiment, the widthof the various turns 65 may be constant or substantially constant. Inother embodiments, the width of turns 65 may vary. A profile orcross-sectional shape of turns 65 may be substantially rectangular orrounded; typically the width of each turn 65 may be greater than itsheight.

A gap, G may exist between adjacent turns 65 of spiral 64, wherein thegap may represent a radial distance between opposing edges of adjacentturns 65. The gap is typically less than the pitch, usually the gap issubstantially less than the pitch, and often the gap is considerablyless than the pitch. The gap between turns 65 of spiral 64 may typicallybe in the range of from about 0.1 mm to 0.5 mm, usually from about 0.15to 0.4 mm, and often from about 0.15 to 0.3 mm. In an embodiment, thegap between adjacent turns 65 may be constant or substantially constant,even though the pitch may be variable. Substantially planar spirals ofelectrically conductive material suitable for forming spiral inductorsare disclosed in commonly assigned, co-pending U.S. patent applicationSer. No. 11/966,895, entitled “High Conductivity Inductively EqualizedElectrodes and Methods,” the disclosure of which is incorporated byreference herein in its entirety.

FIG. 8A schematically represents a spiral inductor, as seen in planview, according to another embodiment of the invention. Spiral inductor62 may be used to form an electrode 60 and/or a ground pad 40. Spiralinductor 62 of FIG. 8A may have a substantially circular or ovalconfiguration. Spiral inductor 62 may include a spiral trace 64 ofelectrically conductive metal including an inner terminus 67 a and anouter terminus 67 b. In an embodiment, spiral inductor 62 may furtherinclude a support layer 68, wherein spiral 64 may be disposed on supportlayer 68 (see, e.g. FIGS. 9A-B). In an embodiment, support layer 68 maycomprise an electrically insulating or dielectric material.

Spiral inductor 62 may include a plurality of turns, from a first turn65 a (radially innermost) to an n^(th) turn 65 n (radially outermost).In an embodiment, n may be from about 10 to 200 or more, substantiallyas described hereinabove. Spiral inductor 62 may have a perimeter,P_(s), and an external surface area A_(s) defined by the perimeter. Theelectrically conductive metal of spiral 64 may occupy at least about 50%of a total surface area A_(s), that is to say, at least about 50 percent(%) of the external surface area of spiral inductor 62 may be occupiedby spiral 64. Typically, electrically conductive metal of spiral 64 mayoccupy from about 60 to 99% of external surface area, A_(s); usuallyfrom about 70 to 99% of external surface area, A_(s); often from about75 to 98% of external surface area A_(s); and in some embodimentselectrically conductive metal of spiral 64 may occupy from about 85% to97% of external surface area, A_(s).

FIG. 8B schematically represents a spiral inductor, as seen in planview, according to another embodiment of the invention. Spiral inductor62 may be used to form a ground pad 40 and/or an electrode 60 forhandpiece 50 according to the instant invention. Spiral inductor 62 mayinclude a spiral trace 64 of electrically conductive metal having aninner terminus 67 a, an outer terminus 67 b, and a plurality of turns,65 a-n, substantially as described for the embodiment of FIG. 8A. Spiralinductor 62 of FIG. 8B may have a substantially square or rectangularconfiguration, a perimeter, P_(s), and a surface area A_(s) defined bythe perimeter. Spiral inductor 62 may include a spiral trace 64 ofelectrically conductive metal. Spiral trace 64 may occupy a percentageof surface area, A_(s) generally as described with reference to FIG. 8A.

It is to be understood that spiral inductor 62 is not limited to asubstantially round or rectangular configuration; instead other shapesfor spiral inductor 62 are also contemplated under the invention (see,e.g., FIGS. 5E-F). As a non-limiting example, each spiral inductor 62may have a substantially trapezoidal shape, e.g., comprising aquadrilateral outline having two parallel sides and two non-parallelsides (see, e.g., FIG. 5E). A spiral electrode having such aquadrilateral outline may also have rounded corners. In anotherembodiment, each spiral inductor 62 may have a substantially arcuateshape or outline (see, e.g., FIG. 5F).

In an embodiment, spiral inductors 62 of FIGS. 8A-B may comprise aspiral 64 which may be at least substantially planar. In an embodiment,spirals 64 and spiral inductors 62 of FIGS. 8A-B may have a slightlycurved or contoured outline (see, e.g., FIG. 9B). In an embodiment,spirals 64 and spiral inductors 62 may be curved or contoured to someextent to accommodate or match a slightly curved or contoured treatmentsurface 53.

FIG. 9A schematically represents a portion of a spiral inductor 62 foran electrode 60, as seen in side view, according to an embodiment of theinvention. (In comparison with FIGS. 8A-B, which show spiral 64 disposedon top of support layer 68, FIG. 9A shows spiral inductor 62 as beinginverted.) As shown in FIG. 9A, spiral inductor 62 may be at leastsubstantially planar.

With further reference to FIG. 9A, spiral inductor 62 may comprise aspiral 64 of electrically conductive metal. In an embodiment, spiralinductor 62 may further comprise a support layer 68, wherein spiral 64may be disposed on support layer 68. In an embodiment, support layer 68may be disposed on treatment surface 53 of handpiece 50. In anotherembodiment, spiral 64 may be disposed directly on treatment surface 53(i.e., support layer 68 may be omitted). In an embodiment, spiral 64 maybe affixed to treatment surface 53 via a layer of electricallyinsulating adhesive. Stated differently, in an embodiment, support layer68 may comprise such a layer of electrically insulating adhesive. Spiral64 may include an external surface 66. External surface 66 may be a baremetal surface of electrically conductive metal spiral 64.

FIG. 9B schematically represents a portion of a spiral inductor 62 foran electrode 40, as seen in side view, according to another embodimentof the invention. As shown in FIG. 9B, spiral inductor 62 may be atleast slightly curved or contoured in outline. Components of spiralinductor 62 in the embodiment of FIG. 9B may be substantially the sameas those shown in FIG. 9A and are omitted from FIG. 9B.

In an embodiment, spiral inductor 62 may be configured for direct (e.g.,bare metal) contact with the patient. For example, in an embodiment abare metal external surface 66 of spiral 64 may be configured forcontacting the patient. In another embodiment, spiral inductor 62 mayinclude a patient-contacting layer (not shown), comprising electricallyconductive or low resistivity material, disposed on spiral 64. A spiralinductor having a patient-contacting layer is disclosed in commonlyassigned, co-pending U.S. patent application Ser. No. 11/966,895,entitled “High Conductivity Inductively Equalized Electrodes andMethods,” the disclosure of which is incorporated by reference herein inits entirety.

FIG. 10A schematically represents a handpiece, as seen from the side,according to one aspect of the invention. Handpiece 50 may includeelements substantially as described hereinabove, including treatmentchamber 59 within shell 51, contact plate 55, and a plurality ofelectrodes 60 disposed on treatment surface 53. In an embodiment,treatment surface 53 may disposed at, or subtend, an angle, α, withrespect to contact plate 55, wherein angle, α is typically in the rangeof from about 95 to 175°, usually from about 100 to 165°, and often fromabout 110 to 160°.

In FIG. 10A, handpiece 50 is disposed against a target region, TR, ofthe patient's skin, SK, such that flange 58 contacts the externalsurface, ES, of the skin. In FIG. 10A, suction port(s) 62 may bedisconnected from vacuum unit 70 (see, e.g., FIG. 10B), and/or vacuumunit 70 may be idle (off). Accordingly, in FIG. 10A treatment chamber 59may be seen as empty, e.g., a void that does not contain target tissueof the patient.

In FIG. 10B, suction port(s) 62 may be connected to vacuum unit 70and/or vacuum unit 70 may be activated (on). Flange 58 may be adaptedfor sealing engagement with the external surface of the skin. Forexample, flange 58 may be configured for sealing treatment chamber 59against the skin (with or without the application of a sealing materialto the skin and/or flange 58). Accordingly, in FIG. 10B target tissue,TT, of the patient may be drawn into treatment chamber 59, such thatelectrode's 60 and treatment surface 53 may contact the patient's skin,and electrodes 60 may at least partially surround the target tissue(see, e.g., FIGS. 5E-F). Electrodes 60 may be disposed proximal toflange 58, i.e., electrodes 60 may be recessed within treatment chamber59 such that electrodes 60 do not contact with the patient's tissue/skinunless the target tissue is drawn into treatment chamber 59.

FIG. 11A is a flow chart schematically representing steps in a method100 for non-invasively treating a patient, according to anotherembodiment of the invention. Step 102 may involve providing anelectrosurgical handpiece having at least a first electrode and a secondelectrode (see, e.g., FIGS. 1A-B, 2C, 5D and 6A). At least one of thefirst and second electrodes may comprise a spiral inductor. At least aportion of the treatment surface may be at least substantially planar.In an embodiment, the treatment surface may occupy at least twodifferent planes. One or more of the spiral inductors may be at leastsubstantially planar, and each spiral inductor may be disposed on atreatment surface of the handpiece. Each spiral inductor may comprise atleast one spiral of electrically conductive metal, and each spiralinductor may include various other elements, features, andcharacteristics as described herein, e.g., with respect to FIGS. 7 and8A-9B.

Each electrode may be configured for effectively applying electricalenergy to the target tissue. The target tissue may be disposed atparticular depths beneath a target region of the patient's skin. Thetarget tissue may be disposed within a layer of subcutaneous fat. Thetarget tissue may be disposed at particular depths above a muscle layerof the patient's body. The thickness or depth of the fat layer and ofthe muscle layer may vary widely from patient to patient and from regionto region of the body of a given patient. Each electrode may beconfigured for effectively applying electrical energy to subcutaneousfat to provide controlled removal, lipolysis, liquefaction, or atrophyof adipose tissue in the targeted region of the patient's body.Advantageously, the instant invention may provide such treatment byselectively heating the targeted subcutaneous fin with little or noheating of adjacent, non-target tissue (skeletal muscle and skin).

Step 104 may involve disposing a ground pad against a non-target regionof the patient's skin. The ground pad may comprise a spiral inductor asdescribed hereinabove, e.g., with respect to FIGS. 7 and 8A-9B.

Step 106 may involve contacting the handpiece against the skin of thepatient. In an embodiment, step 106 may involve contacting the handpieceagainst the skin such that at least the first and second electrodescontact a target region of the skin. In an embodiment, the handpiece mayhave a treatment chamber, and step 106 may involve at least partiallydrawing the target region of skin and underlying target tissue into thetreatment chamber (see, e.g., FIG. 10B). In another embodiment, thehandpiece may have a substantially planar treatment surface, and thehandpiece may lack a treatment chamber (see, e.g., FIGS. 6A-B).

The target region of the skin and the non-target region of the skin maybe non-adjacent to, and remote from, each other. In an embodiment, thetarget region of the skin and the non-target region of the skin may beseparated by at least one layer of subcutaneous fat, at least one layerof muscle, and/or at least one bone of the patient's body. As anexample, the target region may be an anterior (ventral) part of thepatient's body, while the non-target region may be a posterior (dorsal)part of the patient's body. As further non-limiting examples, the targetregion may be in the abdominal region or the thoracic region of thepatient, while the non-target region may be on the hack or buttocks ofthe patient (see, e.g., FIG. 12B, infra).

Step 108 may involve independently controlling or adjusting an electricpotential of each of: the first electrode, the second electrode, and theground pad. In an embodiment, step 108 may involve maintaining theground pad at a reference potential, e.g., ground potential. In anembodiment, step 108 may involve dynamically controlling the electricpotential of the first and second electrodes relative to the referencepotential. In an embodiment, step 108 may further involve controlling apotential difference between the first electrode and the secondelectrode. In an embodiment, controlling the potential differencebetween the first electrode and the second electrode may includecontrolling or adjusting a phase difference between a first AC voltageof the first electrode and a second AC voltage of the second electrode.The phase difference between the first and second AC voltages may bedynamically controlled or adjusted by increasing or decreasing the phasedifference during a procedure. In an embodiment, step 108 may involveindependently controlling an electric potential of each of the firstelectrode, the second electrode, and the ground pad such that each ofthe first electrode, the second electrode, and the ground pad has adifferent electric potential.

Step 110 may involve applying electrical energy to the target tissue viaat least one of the first and second electrodes. As a non-limitingexample, the target tissue may comprise subcutaneous adipose tissuedisposed at various depths beneath the target region of the patient'sskin.

Step 112 may involve sensing temperature values of the target region ofthe skin and/or of the target tissue. The temperature values may besensed by one or more temperature sensors. The temperature sensors maybe disposed on the handpiece, e.g., arranged adjacent to one or more ofthe electrodes. The temperature sensors may be in signal communicationwith a control unit (see, e.g., FIGS. 1B and 3A).

Step 114 may involve dynamically controlling electric currentdistribution within the patient's tissues relative to a depth of thetarget issue such that the target tissue is selectively heated incomparison with adjacent non-target tissue. The target tissue may bedisposed at particular depths beneath the target region of the patient'sskin. In an embodiment, step 114 may involve controlling the electriccurrent distribution within the patient's tissue in response totemperature values sensed in step 112. The electric current distributionmay be sufficient to controllably remove or otherwise modify at least aportion of the target tissue, whereby the appearance of the patient'sbody or a portion thereof is materially enhanced.

In an embodiment, method 100 may be used to effectively treat an area ofthe patient's body of at least about 10 cm², and usually at least about100 cm². Naturally, in an embodiment the handpiece may be moved inrelation to one or more targeted regions of the patient's body duringthe procedure in order to treat a relatively large targeted region ofthe skin of the patient.

FIG. 11B is a flow chart schematically representing steps in a method200 for selectively heating a target tissue of a patient, according toanother embodiment of the invention. Step 202 may involve providing ahandpiece. The handpiece may include a treatment chamber, a plurality ofelectrodes disposed within the treatment chamber, and a flange. At leastone of the electrodes may comprise a spiral inductor, which may besubstantially planar. The treatment chamber may be configured forreceiving at least a portion of target tissue therein. A treatmentsurface of the handpiece may define a portion of the treatment chamber.The electrodes may be disposed on the treatment surface. The flange maydefine a lower perimeter of the treatment chamber. The handpiece mayfurther include various other elements, features, and characteristics asdescribed herein, e.g., with respect to FIGS. 3A, 4, and 5D-F.

Step 204 may involve contacting a ground pad against a non-target regionof the patient's skin. The non-target region may be remote from a targetregion of the patient's skin, and the target region may be separatedfrom the non-target region by at least one layer of subcutaneous fat, atleast one layer of skeletal muscle, and a bone of the patient. Theground pad may comprise a spiral inductor (see, e.g., FIGS. 7 and 8A-B).

Step 206 may involve contacting the flange of the handpiece against atarget region of the skin of the patient. In an embodiment, step 204 mayinvolve contacting the patient's skin with the flange such that theflange surrounds the target region of the patient's skin. The targettissue may comprise subcutaneous fat disposed at particular depthsbeneath the target region of the patient's skin. The depth of the targettissue, as well as the depth of a muscle layer disposed beneath oradjacent to the subcutaneous fat, may vary from patient to patient, aswell as from region to region of the body of a single patient.

Step 208 may involve at least partially drawing the target tissue intothe treatment chamber of the handpiece. In an embodiment, the targettissue may be drawn into the treatment chamber via suction applied tothe treatment chamber. In an embodiment, step 208 may involve drawingthe patient's skin against the treatment surface of the handpiece. Eachof the electrodes may be disposed proximal to the distal rim (i.e.,flange 58) of the handpiece, wherein the electrodes may be recessedwithin the treatment chamber such that the patient's tissue/skin doesnot contact any of the electrodes until the target tissue is drawn intothe treatment chamber (see, e.g., FIGS. 10A-B).

Step 210 may involve maintaining the ground pad at a referencepotential. The reference potential may correspond to ground (earth)potential. Step 212 may involve independently controlling or adjustingthe electric potential of each electrode. The electric potential of eachelectrode may be controlled relative to the reference potential of theground pad. In an embodiment, step 212 may involve dynamicallycontrolling a potential difference between at least two of the pluralityof electrodes mounted on the handpiece. In an embodiment, step 212 mayinvolve increasing or decreasing a phase difference between a first ACvoltage of a first electrode and a second AC voltage of a secondelectrode. In an embodiment, step 212 may involve independentlycontrolling the electric potential of each electrode in response tosensed temperature values of the target region of the patient (see,e.g., FIGS. 1B, 3A, and step 112 of method 100 (FIG. 11A)).

Step 214 may involve applying electrical energy to the target tissue viaat least one of the plurality of electrodes. During step 214, theelectric current distribution relative to the target tissue may bedynamically controlled, via step 212, to provide selective heating ofthe target tissue as compared with non-target tissue, wherein thenon-target tissue may be disposed adjacent to the target tissue. Thetarget tissue may comprise subcutaneous fat disposed beneath the targetregion of the patient's skin. The electrical energy applied in step 214may be controlled (e.g., via steps 210 and 212) to effectively treat orremove at least a portion of the subcutaneous fat, or to improve theappearance of the skin adjacent to the targeted subcutaneous fat.

FIG. 12A schematically represents a portion of a patient's body disposedin relation to a handpiece and a ground pad, according to anotherembodiment of the invention. A portion of the patient's body, includinga target region, TR, of the skin, SK; at least one layer of subcutaneousfat, SF; at least one layer of skeletal muscle, MU; and at least onebone, BN, of the patient, disposed (or “sandwiched”) between handpiece50 and ground pad 40. Handpiece 50 may be disposed against the targetregion of the skin, while the ground pad 40 may be disposed against anon-target region. NTR, of the skin. Handpiece 50 may be disposedadjacent to a target tissue, TT, beneath the skin, while the ground pad40 may be disposed at a location remote from the target tissue. Theinvention is not limited to procedures performed on any particularsequence or orientation of tissue layers.

FIG. 12B schematically represents a patient's body, as seen in themedial direction, including various regions of the body which maycomprise target or non-target regions of the patient, according toanother embodiment of the invention. As non-limiting examples, a targetregion of the patient on or against which handpiece 50 may be disposedduring a procedure for the treatment of cellulite or subcutaneous fatmay include the anterior of the thigh, AT, the posterior of the thigh,PT, the buttocks, BT, the back, BK, the abdomen, AB, the arm, AR, theshoulder, SH, the hip, HP, and the thorax, TH. Similarly, a non-targetregion of the patient on or against which ground pad 40 may be disposedduring a procedure for the treatment of cellulite or subcutaneous fatmay include, without limitation, the anterior of the thigh, AT, theposterior of the thigh, PT, the buttocks, BT, the hip, HP, the hack, BK,the abdomen, AB, and the thorax, TH. (In FIG. 12B, handpiece 50 andground pad 40 are shown, for illustrative purposes, against the abdomenand the back, respectively.) A target region of the skin may be disposedabove or adjacent to a layer of skeletal muscle, wherein the skeletalmuscle may include, without limitation, a thigh muscle, an abdominalmuscle, a thoracic muscle, an arm muscle, a shoulder muscle, or a backmuscle, or combinations thereof. A target tissue of the patient targetedfor treatment according to the invention may comprise subcutaneousadipose tissue disposed between such skeletal muscle layers and thetarget region(s) of skin. It is to understood, however, that theinvention is by no means limited to target tissues in or at the bodyregions specifically labeled or shown in FIG. 12B. Non-limiting examplesof skeletal muscles adjacent to which subcutaneous adipose tissue may betargeted according to the instant invention include: the externaloblique muscle, the pectoralis major muscle, the gluteus maximus muscle,the deltoid muscle, the trapezius muscle, the biceps brachii muscle, thetriceps brachii muscle, the latissimus dorsi muscle, the rectus femorismuscle, the biceps femoris muscle, the vastus lateralis muscle, and thevastus medialis muscle.

It is to be understood that the foregoing relates to exemplaryembodiments of the invention, and that methods and apparatus of theinvention may find many applications other than those specificallydescribed herein. Those skilled in the art may devise various mechanismsfor controlling electric current distribution relative to particulardepths of target tissue beneath the skin, according to the instantinvention, in light of applicant's teachings herein. None of theexamples presented herein are to be construed as limiting the presentinvention in any way; modifications may be made without departing fromthe spirit and scope of the invention as set forth in the followingclaims.

What is claimed is:
 1. A method for treating a patient, comprising: a)providing a handpiece having a first electrode and at least onetemperature sensor configured for sensing temperature values of apatient's skin; b) disposing a ground pad against a non-target region ofthe patient's skin; c) contacting said handpiece against a target regionof the patient's skin, such that said first electrode contacts thepatient's skin; d) determining a temperature value of a target tissuedisposed beneath the skin based on the sensed temperature values of theskin; and e) controlling an electric potential of said first electrodein response to said determined temperature value of the target tissuefor dynamically controlling electric current distribution relative to adepth of the target tissue beneath the skin.
 2. The method of claim 1,wherein the non-target region of the skin is remote from the targetregion of the skin.
 3. The method of claim 1, wherein the target regionof the skin and the non-target region of the skin are separated by atleast one layer of subcutaneous fat, at least one layer of skeletalmuscle, or at least one bone of the patient's body.
 4. The method ofclaim 1, wherein the target region of the skin comprises the skin on theabdominal region or the thoracic region of the patient, and thenon-target region comprises the skin on the back or buttocks of thepatient.
 5. The method of claim 1, wherein the target region of the skinis disposed above or adjacent to a layer of skeletal muscle, and whereinthe skeletal muscle is selected from a thigh muscle, an abdominalmuscle, a thoracic muscle, an arm muscle, a shoulder muscle, and a backmuscle, or combinations thereof.
 6. The method of claim 5, wherein theskeletal muscle is selected from the external oblique muscle, thepectoralis major muscle, the gluteus maximus muscle, the deltoid muscle,the trapezius muscle, the biceps brachii muscle, the triceps brachiimuscle, the latissimus dorsi muscle, the rectus femoris muscle, thebiceps femoris muscle, the vastus lateralis muscle, and the vastusmedialis muscle, or combinations thereof.
 7. The method of claim 5,wherein the target tissue beneath the skin comprises subcutaneousadipose tissue disposed between the skeletal muscle and the targetregion of the patient's skin.
 8. The method of claim 1, wherein step e)comprises: maintaining said ground pad at a reference potential, andcontrolling said electric potential of said first electrode relative tosaid reference potential.
 9. The method of claim 1, wherein thehandpiece comprises a second electrode, and wherein step e) furthercomprises: controlling a potential difference between said firstelectrode and said second electrode relative to said ground pad.
 10. Themethod of claim 9, wherein, during step e), each of said firstelectrode, said second electrode, and said ground pad has a differentelectric potential.
 11. The method of claim 9, wherein step e) comprisescontrolling a phase difference between a first AC voltage of said firstelectrode and a second AC voltage of said second electrode.
 12. Themethod of claim 1, wherein said electric current distribution issufficient to controllably remove or otherwise modify at least a portionof the target tissue beneath the skin.
 13. A method for treating apatient, comprising: a) contacting a first electrode and a secondelectrode against a target region of a patient's skin; b) disposing aground pad against a non-target region of the patient's skin; c) sensingtemperature values of the skin using at least one temperature sensor; d)determining a temperature value of a target tissue disposed beneath theskin based on the sensed temperature values of the skin; and e)controlling the electric potentials of the first and second electrodesin response to said determined temperature value of the target tissuefor selectively heating the target tissue relative to non-target tissue.14. The method of claim 13, wherein controlling the electric potentialscomprises adjusting a phase difference between the electric potentialsof the first and second electrodes in response to said determinedtemperature value of the target tissue.
 15. The method of claim 14,wherein controlling the electric potentials the phase difference betweenthe electric potentials of the first and second electrodes is zero. 16.The method of claim 13, wherein controlling the electric potentials ofthe first and second electrodes comprises dynamically controlling apotential difference between the first and second electrodes.
 17. Themethod of claim 13, wherein the non-target region is disposed at alocation remote from the target region of the skin.
 18. The method ofclaim 13, wherein the target tissue comprises subcutaneous adiposetissue disposed between the patient's skin and a skeletal muscle layer.19. The method of claim 18, wherein the skeletal muscle layer comprisesat least one skeletal muscle selected from the external oblique muscle,the pectoralis major muscle, the gluteus maximus muscle, the deltoidmuscle, the trapezius muscle, the biceps brachii muscle, the tricepsbrachii muscle, the latissimus dorsi muscle, the rectus femoris muscle,the biceps femoris muscle, the vastus lateralis muscle, and the vastusmedialis muscle.
 20. The method of claim 18, wherein the target regionof the skin is disposed above or adjacent to a layer of skeletal muscle,and wherein the skeletal muscle is selected from a thigh muscle, anabdominal muscle, a thoracic muscle, an arm muscle, a shoulder muscle,and a back muscle, or combinations thereof.